<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <title>Title</title>
</head>
<body>
<div id="app">
  <p v-if="con">{{message}}</p>
  <p v-else>色即是空</p>
  <button @click="reverse">变化</button>
</div>

<script src="../js/vue.js"></script>
<script>
  const app = new Vue({
    el: '#app',
    data: {
      message: "你好",
      con: true
    },
    methods: {
      reverse() {
        this.con = !this.con
      }
    }

  })
</script>
</body>
</html>
